This chapter offers an overview of several strands of existing research addressing various aspects of L2 writing and SLA so as to be able to trace signs, both overtly provided by the authors or implicitly emerging from their arguments, of a shared interest in what I call the language learning potential of writing. I review theoretical frameworks informing this body of research, the most prominent themes investigated, and its main research methodology characteristics. Key findings of the studies reviewed are then synthesized and critically discussed from the perspective of the light they shed on the relationship between written output practice and second language development. The chapter concludes with a call for research into the writing-to-learn the language dimension of L2 writing.